While nobody is upset that the preseason is ending, we do have one last look back at the preseason to take before moving on to games that actually matter.

In one sense the preseason is meaningless. It's hard to learn new things about a team in the preseason. The preseason is for learning about individual players, not entire units. That being said, we can have some things confirmed during the preseason, something that was easy to find for the Colts.

In some ways this was good: bright young players confirmed their rise among the NFL's brightest future stars. In other ways it was a much more depressing note, as concerns were confirmed.

So looking at both sides of the coin, what were the ten most important things we learned from the Colts preseason?

Ryan Grigson Loves Potential

This may be more of an August thing than a preseason thing, but it's arguably the most certain item on this list: Ryan Grigson loves high-potential pickups at the end of the roster.

While some teams could be enticed by wiley veterans who hit the waiver wire, using a few solid players (who aren't long-term options) to fill out the roster, the Colts have not been one of those teams. Instead, Grigson has been set on picking up high-potential players who are raw, but have natural athleticism that is not teachable.

For example, just in the last few days, Grigson has claimed tight end Jack Doyle, traded for outside linebacker Cam Johnson and signed Da'Rick Rogers to the practice squad. All three players are very raw, but have the athletic potential to be stars.

The topic can't be discussed without bringing up Caesar Rayford, a 6'7" outside linebacker who had never had an NFL tryout prior to the Colts bringing him in. With five sacks in the preseason, it seems as though that move paid off.

Overall it may be a touch risky, but Grigson is using the bottom of the roster to try to find diamonds in the rough.

Hugh Thornton Has a Real Shot at Starting

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The Colts starting right guard Mike McGlynn was one of the worst linemen in football last season. Pro Football Focus graded McGlynn as the worst overall guard last season, and Football Outsiders tracked the Colts' run plays up the middle as the third-worst, on average, in the league.

No matter how you look at it, the Colts desperately need a change.

Hugh Thornton hopefully is that change.

After missing much of training camp with an injury, Thornton came into the third preseason game and played very well in both pass protection and run-blocking. Thornton moved well, was smart in pass protection and held his ground.

While his second game against Cincinnati was more of a mixed bag, Thornton showed the talent that made him the Colts third-round draft pick in 2013. If any rookie from the Colts 2013 class is going to start this season, it'll be Thornton.

2013 Surprises: Caesar Rayford and Delano Howell

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It seems like every team, every year, has an undrafted free agent or former practice squad player come out of nowhere and play well enough to make the final roster, and sometimes even become a consistent contributor.

Last year, the Colts inside linebacker Jerrell Freeman was that player. This year, outside linebacker Caesar Rayford and safety Delano Howell were the surprise bright spots.

Rayford is a pass-rushing outside linebacker with great length (6'7") and strength that allowed him to notch five sacks during the preseason, the most in the NFL. He comes from an unlikely background, playing in both the AFL and CFL since graduating from the University of Washington in 2009.

At 27 years old, and raw, it's questionable how much he can improve. Right now, he'll give the Colts a body on special teams and a potential pass-rusher.

Howell spent most of last season on Buffalo's practice squad, but was signed by the Colts in late November. With injuries to three of the Colts' top four safeties in training camp, Howell took over starting duties in both training camp and in three of the Colts' four preseason games.

While he didn't light the world on fire, Howell was dependable and overall one of the Colts' most impressive preseason performers.

Pass Protection Woes Are Real

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Even with the addition of guard Donald Thomas and right tackle Gosder Cherilus in the offseason, many Colts fans continue to be concerned about the Colts' pass protection heading into the 2013 regular season.

Last year, the Colts line was one of the worst pass-blocking units in the league, which was an enormous hindrance to offensive coordinator Bruce Arians' downfield-passing offense. While his replacement (Pep Hamilton) should run a more efficient offense that doesn't put the line in as difficult situations, the lack of protection is still a concern.

Last season, the Colts allowed pressure on 38.1 percent of dropbacks, the fifth-highest mark in the league. Obviously, the marks this year are during the preseason, and I wouldn't expect them to continue to be quite that poor during the regular season.

Nevertheless, the pass protection is still a major concern, and to ignore it would be irresponsible.

Pass Rush Concerns Are Also Valid

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As much as the Colts are concerned about protecting the passer, they may be even more worried about their own ability to get to the opposing quarterback.

Little positive signs came from the preseason in that regard: Robert Mathis struggled to make an impact while rookie Bjoern Werner showed flashes, but little else. Little-known Caesar Rayford turned some heads with five sacks, but the bulk of those came against second and third-string linemen, and his impact likely will be minimal in the regular season.

The Colts are concerned, evidenced by their recent trade for OLB Cam Johnson, a pass-rushing specialist from San Francisco.

As Chuck Pagano said on September 2, the Colts can try to manufacture some pressure in other ways than the vanilla pass rush they showed in the preseason, but it's definitely not guaranteed.

T.Y. Hilton Has a Fantastic Future

Through all the concerns, there were a few bright stars in the preseason for Indianapolis.

One was Luck, who we talked about already. Another was T.Y. Hilton, who continued to display his big-play ability with a touchdown in every game he played in, averaging over 16 yards per reception.

Hilton has had a fantastic August, displaying his chemistry with Andrew Luck in training camp and making plays in the preseason. While Darrius Heyward-Bey will get the starts, namely due to his run-blocking ability, the Colts will do what they need to in order to get Hilton on the field.

Chandler Harnish Isn't Ready

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As encouraging as Andrew Luck's play has been, third-string quarterback Chandler Harnish has been just as discouraging.

Harnish is never going to be an option to start, but the hope is that he would progress to a level where he could be a viable backup or trade piece. Unfortunately, that didn't happen during this past offseason.

While some fans I talked to have been more impressed with Harnish than second-string quarterback Matt Hasselbeck in training camp, there was a clear difference between the two in the practices.

When the preseason finally arrived, Harnish continued to show why he was the final pick in the 2012 draft.

Harnish finished the preseason with a completion percentage of 47.1, yards per attempt of 3.5 and a passer rating of 45.9. Generally, he just looked uncomfortable and had difficulties settling into a rhythm. The Colts placed him on the practice squad, and there's time to improve, but Harnish's preseason didn't instill confidence in anybody.

The Colts' Depth on the Defensive Line Is Much Improved

Ryan Grigson spoke back in April about wanting to create a "cauldron of competition" on the offensive line.

Well, it seems he did just that on the defensive side of the ball as well.

The Colts' improved depth on the defensive line played well throughout the preseason, but there were only so many roster spots open. This meant that players like Drake Nevis and Lawrence Guy, both of whom played well in the preseason, were released.

Meanwhile, the Colts' depth defensive linemen include Fili Moala and Ricardo Mathews as well as high-potential youngsters Josh Chapman and Montori Hughes. Mathews and Moala both have starting experience if the two starters go down with an injury, and Chapman and Hughes are supposed to be the long-term answers.

The Colts Want to Run, but Might Not Have the Personnel

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The Colts have talked all summer about running the ball and desiring balance, but the fact is that they simply don't have the personnel to be a strong running team.

Of the Colts starting linemen, only left tackle Anthony Castonzo finished the preseason with a positive run-blocking grade from Pro Football Focus (subscription required). Starting running back Vick Ballard averaged just 3.1 yards per carry during the preseason, and the Colts finished with a minus-14.6 PFF grade overall as a team in run blocking.

The running lanes were particularly clogged on the right side. While the team averaged over 5.3 yards per carry when running behind the left guard or farther outside on the left, they averaged just 2.8 yards per carry when running anywhere from the middle to behind the right tackle.

If the Colts really want to be a power running team, they have to be able to grind out yards up the middle. Unfortunately, right now it doesn't seem like they have the offensive line to do so.